//package com.frank.live.util;
//
///**
// * Tool of transforming YUV format
// * Created by frank on 2018/7/1.
// * YUV是一种颜色编码格式，可以说YUV流媒体是原始流数据，大部分的视频领域都在使用。他与RGB类似，但RGB更多的用于渲染时，而YUV则用在数据传输，因为它占用更少的频宽。当然，实时通讯为了降低带宽都会采用H264/H265编码。从字面意思理解，YUV的含义:Y代表亮度信息（灰度），UV分别代表色彩信息
// */
//
//public class YUVUtil {
//
//  public static byte[] ARGBtoYUV420SemiPlanar(int[] input, int width, int height) {
//
//    final int frameSize = width * height;
//    byte[] yuv420sp = new byte[width * height * 3 / 2];
//    int yIndex = 0;
//    int uvIndex = frameSize;
//
//    int a, R, G, B, Y, U, V;
//    int index = 0;
//    for (int j = 0; j < height; j++) {
//      for (int i = 0; i < width; i++) {
//
//        a = (input[index] & 0xff000000) >> 24; // a is not used obviously
//        R = (input[index] & 0xff0000) >> 16;
//        G = (input[index] & 0xff00) >> 8;
//        B = (input[index] & 0xff);
//
//        // well known RGB to YUV algorithm
//        Y = ((66 * R + 129 * G + 25 * B + 128) >> 8) + 16;
//        U = ((-38 * R - 74 * G + 112 * B + 128) >> 8) + 128;
//        V = ((112 * R - 94 * G - 18 * B + 128) >> 8) + 128;
//
//        // NV21 has a plane of Y and interleaved planes of VU each sampled by a factor of 2
//        // meaning for every 4 Y pixels there are 1 V and 1 U.  Note the sampling is every other
//        // pixel AND every other scanLine.
//        yuv420sp[yIndex++] = (byte) ((Y < 0) ? 0 : ((Y > 255) ? 255 : Y));
//        if (j % 2 == 0 && index % 2 == 0) {
//          yuv420sp[uvIndex++] = (byte) ((V < 0) ? 0 : ((V > 255) ? 255 : V));
//          yuv420sp[uvIndex++] = (byte) ((U < 0) ? 0 : ((U > 255) ? 255 : U));
//        }
//
//        index++;
//      }
//    }
//    return yuv420sp;
//  }
//
//}
